There is a new measure to the advancement and modernity of cities around the world. That measure does not belong to the group of economic or financial yardstick. That degree of modernization is now seen on the skyline. The upward trend of building the spaces that people dwell in. The expansion of towns and cities across the world has jumped into vertical rates in the recent years. The era of skyscrapers have arrived. Buildings that literally touch the clouds, tower over any man-made structures and cast shadows several kilometers long
The vertical growth might be due to the innovation or the heavy amount of competition between countries. It might be because of land scarcity and the skyrocketing prices of real estate. But one trend has emerged – the most advanced cities are building high, instead of wide.
The skyscrapers have drawn in the tourism, commerce, business and trade. It has become the icon of a city. It has brought fame, functionality and profits. It has become the quintessential marking of an advanced and modern world.
These man-made wonders we are looking at does not simply emerge from the ground. It took the most talented engineers, architects, contractors and businessmen. It took hard work, perseverance and will. It took countless working hours. It took blood, sweat and tears.
However, most important element in the mix is science – engineering physics to be exact.
Engineering Physics is the discipline devoted to creating and optimizing engineering solutions through enhanced understanding and integrated application of mathematical, scientific, statistical, and engineering principles. It is a branch of applied physics that bridges the gap between theoretical science and practical engineering with emphasis in research and development, design, and analysis.
In building skyward, it takes the expertise on materials science, applied mechanics, mechanical physics, electrical engineering, aerodynamics, energy and solid state physics.
We’ll look into 2 main innovations in applied physics that allowed skyscrapers to grow from a few storeys in size to the modern skyscraper.
Innovation 1: Elevators
Before buildings can go taller it must solve how it can bring people higher. The first dilemma that struck physicist and engineers is the challenge of lifting people to higher floors efficiently and safely. Engineers knew that elevators does exist, but they cannot guarantee the safety of passengers when riding an elevator. They found inspiration from the invention of Elijah Graves Otis in 1854 during the World’s Fair in New York wherein he rode a cab connected to an elevator rope that is secured with a powerful wagon spring mounted on top of the cab. The spring connects to a set of metal prongs on each side of the elevator. The prongs run along guide rails fitted with a row of teeth when the rope breaks it triggers a chain of friction spring relaxes and forces the metal prongs into the teeth locking the cab in place.
The solution used physics as a way to counter the natural force of physics – gravity.
An elevator has three forces, the force of gravity, a downward normal force from the passenger and the elevator itself and an upward force from the tension in the cable holding the elevator.
This application traces its roots from Newton’s Law. Newton’s Law proved that an elevator when stationary the acceleration is 0. When the elevator is going up passengers are accelerating, which adds more force to the scale and increases in the total weight. When the elevator is going down, the same is true, but the acceleration is negative, subtracting force from the scale and decreasing the elevator’s apparent weight.
The understanding of Newton’s Law has allowed engineers to calculate and establish the safe parameters for an elevator to carry passengers up and down the tallest structures on earth.
Innovation 2: Aerodynamics
As engineers wanted to build taller buildings they faced another problem – the wind. In a glance, wind hitting a concrete building with reinforced steel frames seems to be a normal occurrence. However, as the buildings go higher, the forces of wind gets dangerously wilder. In this case, building a stronger and more durable building is not the easy way out to counter the forces of wind. So engineers turn to aerodynamics.
Aerdoynamics is the study of the properties of moving air, and especially of the interaction between the air and solid bodies moving through it.They have to marry the design of the building to the natural forces of the wind.
This innovation is best exemplified by the Burj Dubai tower. The Burj Dubai currently stands as the tallest man-made structure in the world. It stands at 2,717 feet and it houses 30,000 residences spread out over 19 residential towers, an artificial lake, nine hotels, and a shopping mall. The engineers who built and design this mammoth structure took aerodynamics in unprecedented territories.
Instead of making the building sleeker, thinner and smoother so that the wind can easily glide pass it, they designed the angles to “break down” the wind that smashes it at 2000 feet in the air. It eliminates the forces of the wind by deflecting it and disrupting the powerful vortices. It had separate stalks, which top out unevenly around the central spire. The unusual and odd-looking design deflects the wind around the structure and prevents it from forming organized whirlpools of air current, or vortices.
One of the wind-engineering specialist for the skyscraper, Jason Garber said that: “the amount of motion you’d expect is on the order of 1/200 to 1/500 times its height.” For the BurjKhalifa, this translates into about two to four meters. “It’s not much, but certainly enough to make residents queasy if they can sense this motion. That’s why one of the chief concerns of architects and engineers is acceleration, which can result in perceptible forces on the human body.”
These advanced techniques they employed at Burj Dubai relates back to the law of conservation of energy. Energy may neither be created nor destroyed. Air has no force or power, except pressure, unless it is in motion. When it is moving, however, its force becomes apparent.The breaking of the redirection of the force of the wind made it possible to break its force into small, manageable and safe pieces.
Most of us have been inside a tall building and have worked or lived inside a high-rise structure. It is easy to miss the science behind the technology that brought us to newer heights. But as much as we are in awe of the skyscraping buildings physical structure and functionality, we must be in awe of the basic principles that allowed it to exist.